SOLVED. Middle grade/YA Fantasy boy wins annual contest between four contenders for a sword. [s]

[Patrick]

Potentially a series. Believed to have read in the early 1990's.
Has a medieval setting.
The boy (main character) knows he's the underdog in this year's contest, and plays that to his advantage. The contenders are riding on horses and the winner will claim the sword.
Winning the annual contest has significance and ultimately the MC becomes a respected leader.

Significant events I remember in no particular order.
At one point, there is a gelatinous blob and direct skin contact burns the skin. However, to save others, the MC dives (or at least thrusts his entire arm) into the blob to strike the blob's heart at it's center.

There is a forgotten/abandoned realm which lies beyond the smoking fields. (Which seem to be semi-active lava fields.) Which have acted as a barrier for years. The MC devises boots for the horses and places flasks of water which can drip down the horses legs to cool their feet as they make the trek across.

Potential Spoiler.





The society, which has until this point appeared medieval, also starts to hint at knowledge of electricity which is closely guarded by the priests. The priests use this knowledge to further their mysticism.
However, the MC discovers that there is a strange wire which is running almost hidden from the wall to an iron claw foot tub which may have already taken the life of a queen.

[Genesistrine]

This is John Christopher's The Sword of the Spirits Trilogy - you must have read the omnibus, since the horses part is from the second book, Beyond the Burning Lands, but the queen is electrocuted in the first book.

[Patrick]

Yes! Thank you.

1-The Prince in Waiting
2-Beyond the Burning Lands
3-The Sword of the Spirits

[Genesistrine]

Cheers!

[Kris]

Glad you found your series, Patrick. Here's the link for Genesistrine's find - the first book: The Prince in Waiting by John Christopher.